Do We Rely Too Much On Imaging?

This is a question that is frequently asked each time an institution deliberates the need to expand imaging services. Do we need another CT or MRI machine? Or are we simply ordering too many studies?

Over the past 10 years, much has been written about radiation exposure due to medical imaging. Theories over cumulative radiation exposure and lifetime risks of cancer have gone as far as comparing radiation levels to nuclear reactor catastrophies or nuclear weapon detonations. However, there is still no national standard for the acceptable use of imaging studies. Why is that?

A brief investigation of the changes in medicine over the past 10 years will demonstrate a few reasons why we rely heavily on medical imaging.

Federal hospitalization guidelines: CMS has placed significant focus on hospital admissions in an attempt to reduce cost and improve patient outcomes. As continued focus is placed on criteria for observation or inpatient status, the necessity for an accurate diagnosis has grown. This burden requires an increased amount of testing to be conducted in the emergency department prior to admission status selection, in order to be as accurate as possible and reduce errors.

Surgical treatment: Surgery is steadily moving toward minimally invasive procedures and shorter hospital stays. Additionally, investigations into non-surgical treatments for previously surgical diseases continue (acute cholecystitis, acute appendicitis). Historically, these diagnoses were treated with hospitalization, further diagnostic evaluation, serial examinations, and ultimately surgical intervention. In today’s medical climate, diagnostic imaging is being required in the emergency department, in advance of admission, in order to ascertain a diagnosis and then decide if surgical intervention is warranted. This increases the need for robust access to imaging at all hours of the day to facilitate decision making. Gone are the days of admission for abdominal pain of unclear etiology and serial examination.

Hospital capacity: The number of hospitals and emergency departments across the country continues to decrease despite the increase in our aging population. This leads to the frequent occurrence of hospital crowding which causes many patients to wait to be seen and spend lengthy periods of time in the emergency department awaiting an inpatient bed. How does that effect imaging burden in the ED? An accurate diagnosis with exact definition of the extent of pathology dictates the treatment regimen and the options for outpatient therapy. As we struggle to find room for those who are very sick, anyone who may meet outpatient treatment criteria is pushed to that setting, but that requires accurate diagnostics.

Special Designations: Many hospitals pursue advanced designations for special populations like trauma centers, primary and comprehensive stroke centers, geriatric centers, chest pain centers, atrial fibrillation centers, and pediatric centers. Some of these designations require a dedicated focus and commitment to prioritization of these populations and their diagnostic evaluation. Imaging plays a large role in trauma and stroke. Additionally, developments in stroke endovascular intervention have increased the reliance on CT perfusion imaging and CT angiography resulting in a greater need for rapid access to these modalities.

So, why not simply increase utilization of non-ionizing imaging studies? (i.e.- MRI and ultrasound) MRI is an excellent modality, but not well suited for the emergency setting. The test takes a relatively long period of time to perform, it is still far more expensive than most CT studies (both in required equipment and charges to the patient). And, it cannot be utilized on any patient with a metallic foreign body. Ultrasound, though less expensive, also takes a lengthy period of time to perform and requires extensive training on behalf of the technician resulting in significant variability in quality. This leaves us with a heavy reliance on the more rapid, readily accessible, and less variable imaging modalities, plan film and CT.

In light of the change in medical practice, it is expected that diagnostic imaging, of some sort, take place in most emergency department visits. If your department is struggling because of a lack of access to required imaging, you may hear discussion about the total number of tests being ordered. If that is the case, and examination of the distribution among the physicians in your own department is a good idea. This will likely reveal that there is less variability than expected amongst the physicians, but a higher total amount of imaging being ordered than expected based on old historical norms. In that scenario, review of the discussion above and the changes that medicine is facing may go a long way in helping educate those who are not familiar with the requirements necessary in an emergency department visit today.